Habibi Flashcards
Albumin
Most abundant plasma protein. Large, so it stays in the circulation. Nonspecific carrier molecule that can protect molecules from degradation from being bound to albumin.
Globulins
second most abundant plasma protein. specific molecule carrier (forms specific conformation) Incl: enzymes, immunoglobulins, specific carrier proteins)
Fibrinogen
plasma protein. Is involved in blood coagulation. Gets converted into fibrin by activity of thrombin.
colloid osmotic pressure
is the osmotic pressure caused my protein presence. Increases when protein increases. This is higher in the plasma due to the greater abundance of proteins and therefore, the net movement is into the interstitial compartment . 0.3 mm Hg outward force twd IC.
What is the interstitial compartment composed of?
Collagen fibers, proteoglycans that give a gel like medium to the compartment (hyaluronic acid +protein). Only about 1% of the compartment is made of free-fluid,
Edema
Swelling of the interstitial compartment . Too much free fluid in the IC. May result from changes in osmotic pressure.
What does the gel medium in the interstitial compartment ensure?
- the uniform distribution of nutrients regardless of body position - not affected by gravity.
- maintains optimal spacing between cells
- mechanical support and giving shape to body parts
Lymphatic system
Transfers fluid from IC into the veins. Has phagocytic cells within (in lymph nodes) that help to filter foreign substances out of the blood. Lymph nodes have resident macrophages
Elephantiasis
Occurs due a blockage(filarial worms introduced by mosquitos) in the lymphatic system. Causes an increase in pressure and fluid build up in the interstitial compartment. Swelling and major accumulations of fluid. This can also lead to necrosis of cells due to the decreased flow of nutrients and gases.
Granulocytes
Include basophils, neutrophils and eosinophils which are all also leukocytes. Granulocytes are derived from myeloid stem cells. Polymorphonuclear cells
Erythropoietin
Stimulates differentiation from myeloid stem cells into proerythroblasts
thrombopoietin
stimulates differentiation from myeloid stem cells into megakaryocytes
granulocyte-monocyte colony stimulating factor
stimulate differentiation from myeloid stem cells into monocytes and granulocytes.
monocytes
Are a type of leukocyte that is myeloid stem cell derived. They can later differentiate into macrophages or dendritic cells.
What are the stem cells and intermediate cells involved in the production of erythrocytes?
Myeloid stem cells, proerythroblasts, basophil erythroblast, polychromatophil erythroblast, orthochromatic erythroblast, reticulocyte erythrocyte.
What is hemoglobin A made up of?
4 Heme groups with their corresponding globin peptide. Hemoglobin A has 2 alpha and 2 beta subunits. This is the most abundant type of adult Hb
What forms a heme molecule?
4 pyrroles form 1 protoporphyrin. Iron plus protoporphyrin forms one heme molecule.
What is fetal hemoglobin and what makes it different from adult hemoglobin?
Fetal hemoglobin has 2 alpha and 2 gamma hemoglobin subunits. Fetal Hb has a greater binding affinity for oxygen and can carry 20-30% more oxygen. It is also at 50% higher concentration in fetal blood compared to adult Hb in adult blood
Megoblastic anemia
vitamin b12 and follic acid deficiency - lead to diminished DNA synthesis (which is important for red blood cell production) - causes red blood cells that are bigger than normal (become too big and burst)
Pernicious anemia
similar to megoblastic anemia - absorption of vitamin b12 is impaired in the Gi tract due to an intrinsic factor
Ferritin
storage area and buffer for iron concentrations in the body. It prevents transient anemia by releasing iron into the body when needed.
transferrin
Transferrin is a beta-globulin plasma protein that binds to iron to transport it to the bone marrow for hemoglobin production. Transferrin-iron complex binds to specific receptors on the erythroblasts in the bone marrow followed by endocytosis and delivery of iron to mitochondria for the synthesis of heme.
Platelets
Broken of pieces of megakaryocytes, which are myeloid stem cell derived. Platelets do not have a nucleus but they do have some organelles.
Platelets contain:
- glycoprotein surface receptors that mediate intracellular processes and secretion of various compounds
- calcium
- thromboxane A2
- fibrin stabilizing factor
- growth factors
thromboxane A2
An eicosanoid produced from platelets when activated to do so. Mediates vasoconstriction and local myogenic spasms upon blood vessel damage to reduce local blood flow and prevent blood loss.
Also activates other platelet cells to aggregate
platelet acivation
Platelets are activated by collagen - activation causes the platelets to produce thromboxane a2 and ADP
cyclooxygenase ll
COX ll - enzyme that converts arachidonic acid into thromboxane A2 - becomes active during platelet activation as thromboxane a2 mediates trauma response. Cox ll can be inhibited by aspirin/endomethacin
fibrin stabilizing factor
Produced by activated platelets. It is activated by thrombin. It functions to help form the meshwork of the fibrin threads during clot formation.
thrombin
a proteolytic enzyme which converts fibrinogen to fibrin monomers which can form the fibrin threads. Thrombin also activates fibrin stabilizing factor
prothrombin
factor ll - an alpha globulin produced in the liver due to the action of vitamin K
- it’s proteolytic product is thrombin
prothrombin activator
catalyzes the reaction of prothrombin to thrombin Upon tissue trauma - a number of clotting factors mediate the production of prothrombin activator.
Factor lll
tissue thromboplastin - initiates the extrinsic pathway. It is released from the tissue following tissue trauma. Shorter in terms of clot formation
Factor Xll
Hagemen factor. Upon activation, mediates the intrinsic pathway of blood coagulation.
Factor Vlll
antihemophylic factor - If this is missing, in a male, the male will have hemophilia A - This factor is needed to help activate Factor X. W/o it - clot has a hard time forming - bleeding disease
Factor V
proaccelerin - helps to form prothrombin activator - speeds up this process
glycocalyx
it is a mucopolysaccharide layer adsorbed to the surface of the endothelial cells. It is an anticoagulant that repels clotting factors and platelets thereby preventing activation of clotting. During tissue trauma, this layer is lost which allows clotting factors can activate.
thombomodulin
an alpha-2 globulin bound within the endothelial membrane that binds to thrombin which deactivates it. Anticoagulant that acts a way from the trauma site to ensure no excessive clotting occurs
heparin
When combined with antithrombin lll, the effectiveness of heparin increase 100-1000 fold. Activates other factors that remove thrombin. Secretes by mast cells and basophils
plasminogen activator
When Factor Xll becomes activated during tissue trauma, it initiates a second, slow cascade involved in clot dissolution. This compound causes plasminogen to be converted into plasmin, which is capable of slowly breaking down the fibrin thread. Plasmin = fibrinolysin
megakaryocytes
Formed in the bone marrow. Platelet cells are derived from cell fragments from megkaryocytes
monocytes
develop in the bone marrow and circulate in blood to where they are needed in the tissue. Once in the tissue, they swell and become macrophages
chemotaxis
chemical substances in the tissues cause neutrophils and macrophages to move toward the source of the chemical (inflamed area)
granulocyte-monocyte colony stimulating factor
Produced by macrophages to trigger bone marrow to create more macrophages and things to help with the immune response. Stimulates both granulocyte and monocyte formation
neutrophils
62% of WBC. Uses extensions of membrane called pseudopedia to engulf bacteria. Results in formation of closed chamber around the bacteria. Phagocytic vesicle meets with lysosomes. both lysosomic enzymes and oxidizing agents are used to kill the bacteria ex. superoxides, hydrogen peroxide, hydroxyl ions. Have receptors for complements and antibodies (opsonins)
eosinophils
Granulocyte. Only about 2% leukocytes. Weak phagocytic activities but work particularly well against parasitic infections. They will attach to parasites and release substances that kill the parasites.
- they migrate in large numbers to the infected area. Attach themselves to juvenile forms of the parasite and kill them using things like hydrolytic enzymes (modified lysosomes)
- react to schistosomiasis and trichinella
- detoxify inflammation inducing substances by releasing hydrogen peroxide
basophils/mast cells
0.4% of leukocytes. Similar to large mast cells and are located outside of capillaries. These cells have IgE on their surface. Both mast cells and basophils secrete heparin, an anticoagulant. They both release, histamine, bradykinin, and serotonin. IgE binds to these cells during allergic reactions. These cells are activated by C3a
histimine
Secreted by mast cells and basophils. Increases the porosity of the endothelial layer, increasing movement of water and solutes from the circulation into the tissue. Leads to edema and swelling of the tissue
bradykinin
increases porosity of the endothelial layer. Secretes by basophils/mast cells
walling off
during inflammation, tissue spaces are blocked off with fibrinogen clots, reducing the spread of the infection around the body
soluble compounds
lysozymes, C-reactive proteins, the complement complex-system, cytokines
macrophages
Are derived from monocytes which are formed from myeloid stem cells in the bone marrow. They have lysozymes in them. They have receptors for compliments and antibodies (opsonins)
lysozymes
Enzymes that can attack bacterial cell walls via hydrolysis. They split the bond between N-acetylglucosamine and N-acetylmuramic acid which compromises the bacterial cell walls. Present in macrophages and in the saliva
C-reactive protein
Stimulated by infection and inflammation. Acute phase protein of hepatic origin. Member of pentraxin protein family.
- bind to the surface of damaged cells and bacteria which promotes activation of the compliment system
- facilitates opsonization - bind to bacteria
DIAGNOSTIC PROPERTIES
- increased, but lower levels of CRP indicate viral infection
- higher levels of CRP indicate bacterial infection
C3b
Complement which acts as an opsonin
C5a
chemotactic factor which attracts neutrophils and macrophages. Activate mast cells and basophils
C3a
anaphylatoxin - promotes inflammation. Also triggers the lytic pathways which can damage the plasma membranes of some invading cells
cytokines
biochemical messengers that stimulate leukocyte activity following infection (stimulate development of more WBC following infection). Produced by macrophages,helper T cells
Examples of cytokines include:
- interleukins (1-6), tumor-necrosis factor, granulocyte-monocyte colony stimulating factor, monocyte stimulating factor, granulocyte stimulating factor
interleukin 1
A cytokine produced by macrophages that acts as a proliferation factor. It helps increase the number of undifferentiated cells which can be converted into a number of different WBC
Cellular components
Innate immune system. Natural Killer cells and phagocytic cells
Natural Killer cells
They are in the same family as B and T - lymphocytes. They bind to the surface of virally-infected cells, foreign cells, and some tumor cells. They function by using specific surface recognition. The are present in the placenta. They secrete cytokines. NK cells release granules that cause perforation of target cells. NK cells are activated by interferons. NK cells can also secrete cytokines
interferons
a family of glycoproteins that are produced by virally infected cells or other lymphocytes. They activate NK cells, and other cells through specific membrane receptors, blocking the synthesis of some proteins. They act in a paracrine fashion on neighbouring cells, reducing the DNA replications of viral cells, reducing the spread of the virus. Form the first line of defense against viral infections
polymorphonuclear cells
basophils, neutrophils, eosinophils
igG
immunoglobulin G - constitutes about 75% of our antibodies. reduces functionality of toxins via immunoneutralization. bivalent
igE
immunoglobulin E - involved in allergic reactions. Present on the surface of basophils and mast-cells. Involved in parasitic immunity and allergic reaction. They interact with allergens and by doing so, causes the mast cells to release oxidizing agents and histamines involved in immune and inflammation response.
agglutination`
a way antibodies can inactivate the invading agent - multiple compounds bound to antigens bind together to form a clump
precipitation
antibody binds and renders the compound insoluble
neutralization
antibody covers the toxic site of the antigen
lysis
some antibodies are capable of directly attacking the membrane of the antigen
classical pathway activation
Once the antigen-antibody complex is formed, the constant portion of the antibody will then be able to directly activate C1 of the complement system
antigen-presenting cells
macrophages, B-cells and dendritic cells. Have MHC proteins on their surface
IgA
~15% of antibodies. Major immunoglobulin in sero-mucus secretion. Ex. through: milk, colostrum, saliva, genito-urinary secretion (present on mucus surfaces)
- important for providing passive immunity to the offspring while their immune system is developing
- has 4 binding sites for binding antigens
igM
10% of circulating Ig. pentameric. One of the first antibodies to arrive - aid in the attack against antigenically complex organisms. They cause agglutinization - complex clumping. Allows the macrophage to recognize easily
igD
1% of circulating Ig. Major form on the membrane of B-lymphocytes. May play a role in triggering of lymphocyte differentiation – they act like a receptor on the surface of B cells. Once activated by an antigen, they can secrete more antibodies with a similar binding domain!
Mannose binding lectin
activates the complement system
Antibodies
There are gamma globulins and consist of 2 light chains and 2 dark chains - light and ark chains are connected by a disulfide bond. Bind to antigens, are formed by plasma cells. aka immunoglobulins. Have a variable fragment antigen binding (Fab) domain and a constant fragment crystalline (Fc) domain. The Fc domain can bind complements, leukocytes host tissue once the Fab domain has been bound and activated by the antigen.
epitopes
proteins on the surface of the antigen which antibodies can bind to. aka antigenic determinant domain.
Helper T cells
secrete a number of cytokines once activated. Needed for the immune system to function efficiently. Once activated, helper T cells secrete B-cell proliferation factors. T-cells only recognize antigens when they are bound to MHC proteins on the surface of antigen presenting cells. Helper T cells only bind to MHC ll proteins on antigen presenting cells.
- upon activation, they secrete cytokines and T-cell and B-cell proliferation factors
MHC
major histocombatibility complex. The MHC proteins bind peptide fragments of antigen proteins that are degraded inside antigen presenting cells and then transport them to the cell surface.
Cytotoxic T-cells
killer cells. Involved in invader cell destruction. Secrete perforin compound which mediates hole formation in the invading cell. Cytotoxic compounds can then be injected into the invading cell, resulting in a cascade that leads to apoptosis. Particularly by cells infected by a virus. MHC l proteins on antigen presenting cells activate cytotoxic T-cells.
Class 1 MHC
When on an antigen presenting cell, they activate cytotoxic T-cells. These are found on the surface of all cells except red blood cells
Class 2 MHC
Only on the surface of macrophages and B-cells. Recognized only by Helper T-cells
coreceptors
CD4 and CD8. Involved with the restriction of which cells can interact with which. Killer T cells contain coreceptor CD8 activated by antigen presented with Class 1 MHC. Target cell presents antigen with Class 1 MHC. Helper T cells contain coreceptors CD4 - which are activated by antigens present by Class 2 MHC
Suppressor T-cells
Act as regulatory T-cells. Limits the activity of Helper T cells and cytotoxic T cells. Modulating excessive activity of the immune system.
hematocrit
percentage of the blood taken up by rbcs. lower than 10% decrease in hematocrit percentage could be lethal
colony-forming unit-erythrocyte (CFU-E)
committed cells that become erythrocytes
